Helical marine propeller



Aug. 24, 1943.

E. A. F. PRESSER HELICAL MARINE PROPELLER Filed Oct. 4, 1941 3 Sheets-Sheet l A Home Aug- 1943. E. A. F. PREssER 2,327,453

HELICAL MARINE PROPELLER Filed Oct. 4, 1941 3 Sheets-Sheet 2 E r25: ,4? fi fresser A [tori/q Aug. 24, 1943. E. A. F. PRESSER HELICAL MARINE PROPELLER Filed Oct. 4, 1941 3 Sheets-Sheet 3 lure/11m Erz'c 13 F Fresser A {tor/11 Patented Aug. 24, 1943 v UNITED STATES PATENT OFFICE HELICAL MARINE PROPELLER Eric A. F. Presser, Hammond, Ind.

Application October 4,

1941, Serial No. 413,675

11 Claims. (oi. 17o 17o) The present invention relates to new and useful improvements in helical propellers for marine reducing the centrifuthe water and to produce a centripetal action to counteract the tend- Another object is to provide auxiliary blades for the propeller adapted to act by suction on the water in the region of the hub and to move it forwardly to also assist in reducing vortex at the rear of the hub and to prevent the creation of vacuum at the front end of the propeller.

part hereof, wherein parts throughout and Figure 1 is a rear elevational view of the propeller embodying the present invention.

' Figure 2 is a front elevational view thereof.

Figure 3 is a, side elevational view. Figure 4 is a fragmentary transverse sectional View through the hub and showing the auxiliary group of blades in section.

Figure 5 is a, sectional view through one of the shanks of the propeller blades and showing the auxiliary blade unit in elevation.

Figure 6 is a sectional view through one of the propeller blades taken of Figure 1.

Figure 7 is a detail of one of the blades showing a modified form of fin thereon to eliminate centrifugal action of the blade.

Figure 8 is a fragmentary sectional view taken substantially on a line 8-8 of Figure 7,

Fi ure 9 is a fragmentary sectional view of the substantially on a line 6-6 hub of the propeller showing the manner of connecting the auxiliary blade thereto.

the propeller shaft 1. ally from the hub at a in Figure 6 of the drawings and is connected to the blade by a connecting plate-like portion or face of the plate-like portion Ill adjacent the glade 8 is rounded to merge gradually with the lade.

The sides of the shank 9 forming the ellipse converge adjacent the corners of the portion it remote from the edges of the blade. The shank portion 9 is provided with a reverse pitch in relawhere the blade angle is approximately 45 detrees.

Carried by the propeller, adjacent the hub portion thereof, is an auxiliary blade unit designated generally at H and including blade members l3 disposed longitudinally with respect to the hub and in spaced relation therefrom, the rear ends of the blades l3 being bent inwardly, as shown at M, and suitably connected to each other by a cap M to provide a substantially pointed rear end for the auxiliary member i2 which is spaced rearwardly from the rear end of the shaft 1, as shown to advantage in Figure 3 of the drawings to provide access to the nut employed for securing the shaft to the propeller.

The blades 53 are connected adjacent the rear end of the hub 5 to a ring member M3 by means of screws E5, the ring member being formed with notches i6 adapted to receive the rear edge of the shank portion 9 of the blades to secure the auxiliary blade member I2 against rotation. The ring may also be secured to an adjacent part of the plate-like portion ill by screws or the like i5".

As illustrated to advantage in Figure 4 of the drawings, the faces of the blade members l3 are angularly disposed with respect to the axis of the propeller. As shown more clearly in Figures 1, 3 and 5 the ring member i5 is provided at circumferentially spaced intervals with portions shaped to fit flatly against the inner surface of the blades l3 for detachably securing thereto by the screws E5 to facilitate assembly and removal from the hub, when desired.

The front ends of the blades H are bent radially inwardly at right angles as shown at 16 and have formed therewith an annular member ll having an opening l8 adapted for receiving the propeller shaft 1, the opening l8 also being formed with a key way l9 for receiving the key employed in securing the propeller to the propeller shaft. The shaft is formed with a flange 1 against which the annulus abuts.

The end of the hub 5 is formed with a recess 20 adapted for receiving 9. lug 21 formed on the annulus ill to secure the rear end of the auxiliary blade member against rotation on the hub.

As shown to advantage in Figures 2 and 5 of the drawings, the radially extending ends it of the blades i3 are twisted angularly for a purpose to be presently described. 1

In a propeller of this type, it is commonly known that the blades 8 in acting on the water have a tendency to throw the water centrifugally away from the blades and thus produce a cavitation and resulting vortex extending substantially in the form of a cone axially from the rear end of the hub portion of the propeller. The fins H are provided to overcome this centrifugal action by acting as a wall against which the water is adapted to strike during its radial movement from the hub of the propeller, thereby retaining the water adjacent the hub and preventing the formation of the aforementioned vortex.

The auxiliary blade member i2 further acts to counteract the formation of this vortex by reason of the angular arrangement of the blades i3, as shown to advantage in Figure 4 of the drawings, the trailing edge l3 of the blades l3 being inclined away from the hub to produce a partial vacuum between the trailing edge of the blades 63 and the hub, which causes the water to be drawn inwardly toward the hub as shown by the arrows, the fins l l and the auxiliary blade member ,iil thus cooperating to create a centripetal action upon the water lateral to the hub rather than the usual centrifugal action.

The inclined position of the shank portions ii produces a screw action on the water received from the blades l3 and I4 and thereby causes a tendency of the water to flow forwardly toward the angular lateral front ends 16 of the auxiliary blade unit which acts on the water in a like manner to maintain a normal pressure of water at the front hub portion of the propeller and thus eliminate the possibility of creating any vacuum in the region of the front end of the hub.

In Figures '7 and 8 I have illustrated a modified form of fin construction comprising an angular flange 22 on the base of the fin adapted to receive screws or other fastening devices 23 for detachably securing the fins to blades of previously manufactured propellers of the conventional helical type.

While I have illustrated a type of propeller having a single fin on each blade, it will be understood that in larger propellers additional fins may be added where necessary for more effectively accomplishing the desired purpose. If a propeller needs only one fin, it is to be placed at a distance from the hub where the blade angle is approximately 45 degrees. If a propeller needs more than one fin, all additional fins must be between the first named fin and the hub.

It is believed the details of construction and manner of use of the device will be readily understood from the foregoing without further detailed explanation.

Having thus described the. invention what is claimed as new is:

1. A propeller of the screw type comprising a hub, a plurality of blades projecting from the hub, said blades having helical pitch angles, and means carried by the hub of the propeller and extending longitudinally of the hub in spaced relation therefrom for producing a centripetal action on the water contacted by the blades.

2. A propeller of the screw type comprising a hub, a plurality of blades projecting from the hub, said blades having a predetermined pitch,

and means carried by the hub of the propeller and disposed in longitudinally spaced relation therefrom for acting on the water to reduc vorteX at the rear end of the hub.

3. A propeller of the screw type comprising a hub, a plurality of blades projecting from the hub, said blades having a predetermined pitch, means carried by the blades for producing a centripetal action on water contacted by the blades, and means carried by the hub of the propeller for urging the water forwardly relative to the bodily movement of the propeller.

4. A propeller of the screw type comprising a hub, a plurality of blades projecting from the hub, said blades having a predetermined helical and reverse pitch, fins carried by the blades adapted to reduce centrifugal action of the blades, and auxiliary blades carried by the hub of the propeller for urging the water inwardly toward the hub and forwardly relative to the bodily movement of the propeller.

5. A propeller of the screw hub, blades projecting radially from the hub, a spiral shank between the hub and the blade, said shank spacing the inner end of the blade from the hub and having a reverse pitch with relation to the pitch of the blade and a platelike connecting portion between the blade and the shank defining longitudinal channels between the blade and hub.

6. A propeller of the screw type comprising a hub, blades projecting radially from the hub, a spiral shank between the hub and the blade, said shank spacing the inner end of the blade type comprising a from the hub and having a reverse pitch with relation to the pitch of the blade and a platelike connecting portion between the blade and the shank defining longitudinal channels at each side of the shank between the blade and hub.

7. A propeller of the screw type comprising a hub, blades projecting radially from the hub, a spiral shank between the hub and the blade, said shank spacing the inner end of the blade from the hub and having a reverse pitch with relation to the pitch of the blade and a plateconnecting portion between'the blade and shank defining longitudinal channelsat each side of the shank between the blade and hub and auxiliar blades disposed in said channels and adapted to feed waterinto the channels.

8. A propeller of the screw type comprising a hub, blades projecting radially from the hub, a spiral shank between the hub and the blade, said shank spacing the inner end of the blade from the hub and having a reverse pitch with relation to the pitch of the blade and a platelike connecting portion between the blad and the shank defining longitudinal channels at each side of the shank between the blade and hub, and a detachable auxiliary blade unit secured to the propeller and including blades disposed and adapted to feed water into the channels.

9. .A propeller of the screw type comprising a hub, blades projecting radially from the hub, a spiral shank between the hub and the blade, said shank spacing the inner end of the blade from the hub and having a reverse pitch with the pitch of the blade and a platelike connecting portion between the blade and the shank defining longitudinal channels at each side of the shank between the blade and hub, an auxiliary blade unit including blades positioned in the channels for feeding water thereto, and means for detachably securing the auxiliary unit to the propeller.

10. A propeller of the screw typ comprising a hub, blades projecting radially from the hub, a spiral shank between the hub and the blade, said shank spacing the inner end of the blade from the hub and having a reverse pitch with relation to the pitch of the blade and a plate-like connecting portion between th blade and the shank defining longitudinal channels at each side of the shank between the blade and hub, an auxiliary blade unit including blades positioned in the channels for feeding water thereto, means connecting one end of the auxiliary blades together, and an annular member connecting the auxiliary blades adjacent their other ends, said annular member engaging the propeller for securing the auxiliary blades in a fixed position.'

11. A propeller of the screw type comprising a hub, blades projecting radially from the hub, a spiral shank between the hub and the blade,

said shank spacing the inner end of the blade from the hub and having a reverse pitch with relation to the pitch of the blade a plate-like connecting portion between the blade and the shank defining longitudinal channels at each side of the shank between the blade and hub, an auxiliary blade unit including blades positioned in the channels for feeding water thereto, said unit also including blades at each end thereof for feeding water forwardly from the channels, and means for detachably securing the auxiliary unit to the propeller.

ERIC A. F. PRESSER. 

